Intercorrelations of Chlorinated Paraffins, Dechloranes, and Legacy Persistent Organic Pollutants in 10 Species of Marine Mammals from Norway, in Light of Dietary Niche

Short-, medium-, and long-chain chlorinated paraffins (CPs) (SCCPs, MCCPs, and LCCPs) and dechloranes are chemicals of emerging concern; however, little is known of their bioaccumulative potential compared to legacy contaminants in marine mammals. Here, we analyzed SCCPs, MCCPs, LCCPs, 7 dechloranes, 4 emerging brominated flame retardants, and 64 legacy contaminants, including polychlorinated biphenyls (PCBs), in the blubber of 46 individual marine mammals, representing 10 species, from Norway. Dietary niche was modeled based on stable isotopes of nitrogen and carbon in the skin/muscle to assess the contaminant accumulation in relation to diet. SCCPs and dechlorane-602 were strongly positively correlated with legacy contaminants and highest in killer (Orcinus orca) and sperm (Physeter macrocephalus) whales (median SCCPs: 160 ng/g lw; 230 ng/g lw and median dechlorane-602: 3.8 ng/g lw; 2.0 ng/g lw, respectively). In contrast, MCCPs and LCCPs were only weakly correlated to recalcitrant legacy contaminants and were highest in common minke whales (Balaenoptera acutorostrata; median MCCPs: 480 ng/g lw and LCCPs: 240 ng/g lw). The total contaminant load in all species was dominated by PCBs and legacy chlorinated pesticides (63–98%), and MCCPs dominated the total CP load (42–68%, except 11% in the long-finned pilot whale Globicephala melas). Surprisingly, we found no relation between contaminant concentrations and dietary niche, suggesting that other large species differences may be masking effects of diet such as lifespan or biotransformation and elimination capacities. CP and dechlorane concentrations were higher than in other marine mammals from the (sub)Arctic, and they were present in a killer whale neonate, indicating bioaccumulative properties and a potential for maternal transfer in these predominantly unregulated chemicals.


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oxychlordane, trans-chlordane, cis-chlordane, trans-nonachlor and cis-nonachlor d The sum of α-HCH, β-HCH and γ-HCH e The sum of BDE-28, -47, -99, - -153, -154, -183, -196, -202, -207, -208 and -209.PBEB and DPTE were also analyzed but under the limit of detection (LOD) in all samples.Supporting Method Text: Chlorinated paraffin and dechloranes analysis Blubber was homogenized with sodium sulphate and extracted using a cold column technique using acetone and n-hexane (1:1) with additions of internal standards ( 13 C-labelled 1,5,5,6,6,10 Florisil cleanup removed the majority of confounding POPs, however toxaphene, chlordanes and nonachlor could not be removed and therefore lead to some uncertainty for SCCP and MCCP results.The LCCP analysis was unaffected by the presence of PCBs and pesticides due to differences in quantification.Values were blank corrected, and the limit of detection (LOD) was calculated as three times the standard deviation of the blank values and the limit of quantification (LOQ) as ten times the standard deviation of the blank values for each contaminant, respectively.
Supporting Table S3.Limit of detection (LOD), limit of quantification (LOQ), mean chlorination degree, and % found in all samples of all chlorinated paraffins and dechloranes analysed

Figure S2 :
Principle component analysis (PCA) biplot of the patterns of homologue groups of short-, medium-and long-chain chlorinated paraffins in blubber in nine species of marine mammal from Norway 2015-2020 (n=38), including sub-adult female minke whales.Response loadings are represented by arrows, coloured from light grey to black by increasing carbon chain length.Each species are represented by unique colours.The ellipses represent 40% prediction areas for each species for multivariate normal distribution.The percentage of the total variation explained by PC1 and PC2 are given in brackets on each axis.
Patterns of all organohalogen contaminants in blubber of 10 species of marine mammals sampled from Norway 2015-2020.Species are ordered from lowest to highest mean δ15N values Supporting Figure S4: Patterns of short-, medium-and long-chain chlorinated paraffins (SCCPs, MCCPs, LCCPs, respectively) and dechloranes in blubber of 10 species of marine mammals sampled from Norway 2015-2020.Species are ordered from lowest to highest mean δ 15 N values

Table S2 :
Median and range (in parentheses) δ 13 C and δ 15 N values in skin and muscle, and sample size, of stranded and harvested (common minke whale) marine mammals from Norway 2015-2020.

Table S4 .
Limit of detection (LOD), mean recovery and % found in all samples of all legacy pollutants and emerging brominated flame retardants analyzed.The laboratory is accredited by the Norwegian Accreditation for the determination of OCs and BFRs in biological matrices of animal origin according to the requirements of NSEN ISO/IEC 17025:2005 (Test 137).The laboratory is accredited for all analytes in the present study with the following exceptions:, PBT, PBEB, DPTE and HBB.The method for determining non-accredited analytes was performed and validated following the same principles as the accredited standard (NS-EN ISO/IEC 17025).

Table S5 .
Redundancy analysis model summaries.Explanatory variables present in the best model are indicated in bold, and the percentage of the total variation estimated by the full model indicated in parentheses.With species as an explanatory variable

Table S6 :
Total area (TA), Bayesian stable isotope standard ellipse area (SEA), Bayesian stable isotope standard ellipse area corrected for small sample size (SEA C ) of four species of marine mammal sampled from coastal and Arctic Norway 2015-2020.The probability of each niche width (SEAC) being larger than another is also indicated, as well as the proportional ellipse overlap, in a pairwise fashion.

Table S7 :
Correlation coefficients (Rho) and p-values (in italics) for pairwise correlation tests between contaminants using Spearman's Rank correlation.P-values are corrected for multiple testing using the Benjamini & Holmberg false discovery rate method.Summary of chlorinated paraffin and dechlorane concentrations (ng/g lw) in blubber of other whale species referenced in the present study.Concentrations are reported as median and range unless otherwise indicated.Studies are reported in alphabetical order by first author, and all references are reported in main text and listed in reference list.